PHP Manual - collected by Jimbob 2006.03
cosh
(PHP 4 >= 4.1.0, PHP 5)
cosh -- Hyperbolic cosine
Description
float
cosh ( float arg )
Returns the hyperbolic cosine of arg,
defined as (exp(arg) + exp(-arg))/2.
See also:
cos(),
acosh(),
sin(), and
tan().